The invention relates to a method of and an apparatus for filling an adhesive in the cracks developed in a concrete structure, or in gaps developed between a concrete structure and the outer material, or other like portions of a structure to be repaired.
Cracks developed in structures made of concrete or stones are generally repaired by filling putty or adhesive therein.
Recently a method was proposed whereby adhesive supply pipes are fixed along the cracks at appropriate space intervals with the remaining spaces sealed and, upon hardening of the sealing material, said pipes are coupled to a supply pump to fill adhesive in the cracks (Japanese Pat. No. 251791).
While cracks can be effectively repaired according to this method, some difficulties are encountered in the operation. For example, increase in the rate at which adhesive is filled in the cracks may cause increase in the pressure applied to the cracks owing to the viscosity of the adhesive and thus the hardened sealing material may be ruptured or the cracks widened. Therefore according to such method, adhesive must be filled at as slow a rate as 3 to 5 minutes per one adhesive-filled portion and thus workmanship is required.
To eliminate those drawbacks, another method was recently proposed whereby adhesive is reserved temporarily in a pressure buffer portion to deaden the pressure applied to the adhesive-filled portion such as cracks, whereupon the reserved adhesive is filled by the gradual and continuous contraction of said pressure buffer portion (Japanese Patent Kokai No. 2367/1981). This was followed by proposal of an adhesive filler apparatus to be used in said second method, which apparatus is equipped with a check valve device for preventing the adhesive from flowing backward (Japanese Patent Kokai No. 87866/1982).
The last-mentioned apparatus made an automatic adhesive filling possible utilizing elasticity of the rubber-made adhesive reserver tube in the pressure buffer portion, which tube, fed with adhesive, can contract of itself gradually and continuously, resulting in considerable reduction of hands required. Further, filling of adhesive into as minute cracks as less than 0.2 mm wide, which was possible only with difficulty, was made practicable. Consequently, it was also made possible to fill adhesive as deep as to the cracks caused, for example, between concrete and the reinforcement steel bars. Meantime, however, the method required the operator to attach a hose connected with a pump to, and, after feeding the apparatus with adhesive, detach the hose from, the apparatus in such high, unstable position as on a trestle, ladder or the like as when repairing the underside of a bridge.
In order to eliminate such drawbacks of the prior art apparatus and method, the present inventors proposed a new apparatus and a method in the Japanese Patent Application No. 238973/1983.
The apparatus proposed therein comprises an injector and a support portion, said injector including a pressure buffer tube, a coupler member adjacent one end of said tube and a check valve between said tube and the coupler member, the other end of said pressure buffer tube being closed, said support portion having a coupler projection which can be easily fitted in said coupler member and a base member for locating the support portion on the crack, etc., said check valve, urged by the adhesive fed in the tube, closing the flow passage of the adhesive and opening said passage when pressed by said coupler member upon coupling the injector to said support portion. This apparatus obviated said drawbacks and enabled an adhesive to be filled in the cracks in concrete structure, etc. by an easy operation of feeding said injector with adhesive via said coupler member using a hose connected to a pump, etc. by pressing the check valve with the nozzle of the hose from the coupler member side, coupling the fed injector to said support portion fixed on the crack, thereby pressing the check valve to restore the passage of adhesive and allowing the adhesive to be filled in the crack. However, where the cracks, etc. require to be filled with relatively a great amount of adhesive, several such injectors have to be used thereon, one after another.
The present invention is an improvement over the last-mentioned apparatus enabling the supplementation of adhesive into the pressure buffer tube emptied without the necessity of once detaching the injector from the support portion fixed on the crack, etc.